An ever present objective of semiconductor assembly is to provide packages for enclosing/encasing semiconductor components that are smaller, thinner, cooler, and less expensive to manufacture at a high rate of production. One type of semiconductor package is the Plastic Dual In-line Package (PDIP). Another type of semiconductor package is the gull-wing Small Outline (SO) package. These semiconductor packages generally include leads (connectors) extending from the sides of the package. Other types of semiconductor packages are flat lead-less packages, such as Dual Flat No-leads (DFN) and Quad Flat No-leads (QFN) packages. A DFN package has lead lands on only two sides of the perimeter of the package bottom, while a QFN package has lead lands on four sides of the package bottom.
Some DFN and QFN package sizes can range from one millimeter (1 mm) by two millimeter (2 mm) packages having three (3) lead lands, to ten millimeter (10 mm) by ten millimeter (10 mm) packages having sixty-eight (68) lead lands. Because the lead-frame is on the bottom of the package, flat no-lead packages can provide superior thermal performance when compared to leaded packages having similar body size and lead counts. Further, in a flat no-leads configuration, the die-attach-pad can be exposed on the bottom exterior of the package, allowing it to be soldered directly to a printed circuit board, and providing a direct route for heat to dissipate away from the package. The exposed die-attach-pad, often referred to as an exposed thermal pad, may greatly improve heat transfer out of the integrated circuit package and into the printed circuit board.